Electrical outlet attachment



May 5, 1964 1. s. BLONDER ELECTRICAL OUTLET ATTACHMENT Filed June 25,1962 FIG-l INVENTOR ISAAC S. BLONDER ATTORNEYS 1 United States Patent,Oiiice 3,131,985 Patented May 5, 1964 The present invention relates toan electrical outlet attachment land, more particularly, to anelectrical outlet attachment which may be locked to prevent unauthorizeduse of the electrical outlet.

Due to the large and increasing use of television set installations andother electrical equipment in public areas, such as in schools and thelike, there has arisen a need tor means to prevent unauthorized use.Attachments with locking means have been proposed for mounting uponelectnical outlet switch plates and the like to prevent suchunauthorized use. Such attachments, however, require close andrelatively costly manuiacturing tolerances to prevent entrance of dustand and to prevent rattling as a result of building vibrations. Further,the devices proposed are not as tamper-proof as might be desired.

it is, therefore, an object of the present invention to provide a newand improved outlet attachment tor mounting on electrical switch platesand the like, which-attachment is not subject to the befiore-mentioedshortcomings.

Another object is to provide a new and improved cover attachment of moregeneral utility, as well.

further objects will become apparent in the description to follow andwill be more particularly pointed out in the appended claims.

In summary, the objects of the present invention are attained in alocking attachment for mounting upon an electrical outlet plate and thelike, having, in combination, a planar plate provided with inwardlyinclined side edges and means for securing the planar plate injuxtaposition with an electrical switch plate and the like. A box-likecover is provided having side walls which incline to converge toward itscover surface, the incline being slightly greater than that of the saidplanar plate side edges to enable resilient-engaging closing actiontherebetween. A hinge disposed within the cover at the lower end of theplanar plate enables closing of the cover against the action of gravity,and the hinge is sufliciently within the cover to prevent tampering. Alock disposed toward the upper end of the cover is provided with aneccentrically-mounted cam rotatable in a plane intersecting the topside-wall of the cover at a region closer to the said cover surface thanto the planar plate when the cover is closed thereupon. The lower of anL-shaped locking catch extends from the top edge of the planar plateinward of the inclined top sidewall at an incline slightly less thanthat of the top side-wall further to permit aresilient closing actionbefore locking in cooperation with the said top side wall, the length ofthe said lower arm. of the L-shaped catch being sutficient to cause thesubstantially vertical arm of the L to extend in a plane slightly closerto the cover surfiace than the camwhen the L-shaped catch is resilientlyclosed within the cover in order to enable the cam rotatably to engagethe inner surface of the vertical arm to secure the cover to the planarplate without substantial play. i

The invention will now be described in connection with the drawing inwhich,

FIG. 1 is a perspective view, partly broken away to illustrate detailsof construction, showing a preferred form of the invention as applied toa wall outlet; I

FIG. 2 is a similar view of the attachment of FIG. 1 demounted from theoutlet and partially opened;

FIG. 3 is a partial view of upper portion of the attachment; and

FIG. 4 is a section view taken upon the line 44 in FIG. 2, looking inthe direction of the arrows.

'Referring to FIG. 1, the locking attachment 1 is shown applied to anelectrical outlet plate :18. The attachment 1 is provided with abox-like cover 2 and a rear planar plate 3, apertured at 17 to exposethe electrical outlet, part of which is shown at 18', such asatelevision antenna cable jack or other connector, with the plate 3secured to the outlet plate 18 as by screws 19. The planar plate 3 isalso provided with inwardly inclined side edges 4 and t 5, and the cover2 has corresponding side walls -6 and 8 which incline convergentlytoward the front surface of the cover 2, with the incline of the sidewalls 6 and '8 preferably slightly greater than that of the side edges 4and 5 to enable the illustrated resilient-engaging closing actiontherebetween. In this manner, when the cover 2 is closed, as in FIG. 1,the side walls 4-6 and 58 are overlapping engaged, eliminating rattlingdue to vibrations, preventing the influx of dust and dirt, and, furtherserving to discourage tampering since screw drivers and the like cannotreadily be inserted to enable forcing of the cover.

Further to prevent tampering with the locking attachment and toeliminate rattling, an L-shaped locking catch 11 employed, the longer orupper arm of which extends outward from the top edge of the'planar plate3 at an incline slightly less than that of the top sidewall 7 of thecover 2, thus enabling a resilient overlapped closing action at the top,also.

- side wall 9 of the cover 2, enabling the cover 2 to pivot to an openposition, FIG. 2, under the action of gravity, and to be moved to theclosed position of FIG. 1 against the action of gravity. The hinge 16 isactually preferably disposed the cover 2, as shown, thus concealing thesame further to prevent tampering.

A lock 14, shown disposed toward-the upper end of the cover 2, isprovided with a key-movable eccentricallymounted cam arm 15, rotatablein the direction of the arrow, FIG. 1, in a plane intersecting the topside wall 7 of the cover 2 at a region closer to the trout cover surface2 than to the rear planar plate 3, when the cover is closed thereupon,in order to eliminate the necessity for recessing extending arm 11' ispositioned slightly closer to the cover surface 2 than the plane of thecam arm 15. As is clearest in FIG. 4, moreover, the catch arm 11 isitself preferably at an incline to the plane of the rear plate 3, beingclose-r thereto at the right end thereof in FIG. 4, than at the leftend, in order to increase the engaging pressure between the cam arm .15and the inner surface of the catch arm 11' as the cam arm 15 is rotatedtoward the locked position.

Modifications will, of course, occur to those skilled in the art andsuch are considered to fall the spirit and scope of the invention asdefined in the appended claims.

What is claimed is:

1. A locking attachment for mounting upon an elec trical outlet plateand the like, having, in combination, a planar plate provided with sideedges and means for securing the planar plate to an electricaloutletplate and the like, a box-like cover the side walls of which inclineconvergently toward its cover surface to enable overlapopening of thecover and to conceal the hinge means wit-l1- in the cover, locking meansdisposed towardthe other end of the cover comprising an eccentric camarm rotatable in a plane intersecting the inclined cover side wall atthe said other end of the cover at a region closer to the said coversurface than to the planar plate when the cover is closed thereupon, andan L-shaped locking catch for cooperating with the locking. means havingoutwardly extending and substantially-vertically extending arms, theoutwardly extending arm protruding from the planar plate outwandtherefrom at an incline slightly less than that or the said side wall atthe said other end of the cover, further to permit an overlappingclosing action, the length of the said outwardly extending arm of thesaid L-shaped catch being suflicient to cause the substantiallyvertically I extending arm of the catch to be disposed slightly closertrical connections to which access is provided when the I said cover isopened about the said hinge means.

3. A locking'attaehment as claimed in claim 1 and in which the saidvertically extending arm of the catch is itself disposed slightlyinclined with respect. to the plane of the said planar plate.

4. A locking attachment as claimed in claim 1 and in which the said oneend of the cover is the lower end and the said other end of the cover isthe upper end thereof.

5. A locking attachment for mounting upon an electrical outlet plate andthe like, having, in combination, a planar plate provided with inwardlyinclined side edges and means for securing the planar plate injuxtaposition with an electrical outlet plate and the like, a box-likecover the side walls of which incline convergently toward its coversurface with the incline being slightly greater than that of the saidplanar plate side edges to enable resilientengaging closing actiontherebetween, hinge means disposed Within the cover at the lower end ofthe planar plate toenable pivotal closing and opening of the cover andto conceal the hinge means within the cover, locking means disposedtoward the upper end of the cover and c0mprising an eccentric cam armrotatable in a plane intersecting the top inclined side wall of thecover at a region closer to the said cover surfiacethan to the planarplate when the cover is closed thereupon, and an L-shaped locking catchone arm of which extends outwardly and the other substantiallyvertically downwardly, the said one arm extending from thetop edge ofthe planar plate inward of the said cover top inclined side wall and atan incline slightly lessthan'th-at of the topside wall, further topermit a resilient closing action before locking in cooperation with thetop side wall, and the length of the said one arm of the Leshaped.catchbeing sufiicient to cause the other substantially. verticallyextending arm of the catch to ertend downwardly in a plane slightlycloser to the cover surface than the cam arm-when the L-shaped catch isresiliently closed'within the cover, in order to enable the cam armrotatably to. engage the inner surface of the vertically extending catcharm, thereby securing the cover to the planar plate without substantialplay, the vertical arm being positioned closer to the planar plate atone end thereof andinclining away therefrom in order to increase theengaging pressure between the cam arm and the innersurf ace of thevertically extending catch arm as the camarmrotatablyengages the saidinner surface.

2,209,015 Bart July 23, 1940 2,987,909 Shlank June13, 1961 FOREIGNPATENTS 5 5,750

Germany Oct. 7, 1933

1. A LOCKING ATTACHMENT FOR MOUNTING UPON AN ELECTRICAL OUTLET PLATE ANDTHE LIKE, HAVING, IN COMBINATION, A PLANAR PLATE PROVIDED WITH SIDEEDGES AND MEANS FOR SECURING THE PLANAR PLATE TO AN ELECTRICAL OUTLETPLATE AND THE LIKE, A BOX-LIKE COVER THE SIDE WALLS OF WHICH INCLINECONVERGENTLY TOWARD ITS COVER SURFACE TO ENABLE OVERLAPPING CLOSINGACTION BETWEEN THE COVER SIDE WALLS AND THE SAID PLANAR-PLATE SIDEEDGES, MEANS DISPOSED WITHIN THE COVER CONNECTING ONE END OF THE COVERWITH THE ADJACENT END OF THE PLANAR PLATE TO ENABLE PIVOTAL CLOSING ANDOPENING OF THE COVER AND TO CONCEAL THE HINGE MEANS WITHIN THE COVER,LOCKING MEANS DISPOSED TOWARD THE OTHER END OF THE COVER COMPRISING ANECCENTRIC CAM ARM ROTATABLE IN A PLANE INTERSECTING THE INCLINED COVERSIDE WALL AT THE SIDE OTHER END OF THE COVER AT A REGION CLOSER TO THESAID COVER SURFACE THAN TO THE PLANAR PLATE WHEN THE COVER IS CLOSEDTHEREUPON, AND AN L-SHAPED LOCKING CATCH FOR COOPERATING WITH THELOCKING MEANS HAVING OUTWARDLY EXTENDING AND SUBSTANTIALLY-VERTICALLYEXTENDING ARMS, THE OUTWARDLY EXTENDING ARM PROTRUDING FROM THE PLANARPLATE OUTWARD THEREFORM AT AN INCLINE SLIGHTLY LESS THAN THAT OF THESAID SIDE WALL AT THE SAID OTHER END OF THE COVER, FURTHER TO PERMIT ANOVERLAPPING CLOSING ACTION, THE LENGTH OF THE SAID OUTWARDLY EXTENDINGARM OF THE SAID L-SHAPED CATCH BEING SUFFICIENT TO CAUSE THESUBSTANTIALLY VERTICALLY EXTENDING ARM OF THE CATCH TO BE DISPOSEDSLIGHTLY CLOSER TO THE SAID COVER SURFACE THAN THE CAM ARM ITSELF INORDER RESILIENTLY TO CATCH AND FORCE THE CAM ARM INTO LOCKING ENGAGEMENTWITH THE INNER SURFACE OF THE SUBSTANTIALLY VERTICALLY EXTENDING CATCHARM, THEREBY SECURING THE COVER TO THE PLANAR PLATE WITHOUT SUBSTANTIALPLAY.